The invention relates to a method for ascertaining an edge layer characteristic of a component. In addition, the invention relates to a device for ascertaining an edge layer characteristic of a component, in particular a component for an aircraft engine.
The surfaces of highly stressed components are treated in order to increase their service life. Methods and devices for surface treatments of components are known in different configurations from prior art. Surface-treatment methods can be carried out basically by machining, lapping, eroding, coating or cleaning. For example, DE 10 2007 009 470 A1 discloses a method and a device for surface peening a component for a gas turbine of an aircraft engine. In this case, an abrasive material such as, for example, steel shot, is applied to at least one region of the surface of the component in order to obtain a surface hardening and thus an increase in the service life.
The quality of the surface treatment, i.e., the residual stress state and solidification condition of the treated component surfaces, which are introduced into the edge layer, can subsequently be determined, for example, by X-ray diffraction with electrochemical erosion or by the so-called borehole method, in order to establish a service life prognosis. However, in this case, destructive test methods are involved. In addition, an indirect monitoring by means of reference samples (Almen plates) that are hardened with the component can be carried out on individual, well-accessible component regions. However, this makes possible only very limited information on the quality of the entire solidified region of the component. Alternatively, it is known to evaluate the quality of the surface treatment by synchrotron radiation or by neutron scattering. These types of measurement methods, however, require an enormous apparatus expenditure as well as the use of radioactive radiation sources and also only make possible the measuring of the simplest component geometries with low spatial resolution.